Distribution of motors for aircraft



Jan. 3, 1928. 1,655,362

H. FARMAN DISTRIBUTION MOTORS FOR AIRCRAFT Original Filed March 13, 1924 Patented Jan. 3, 1928.

UNITED STATES PATENT oFFIcE.

HENRY FARMAN, OF PARIS, FRANCE.

DISTRIBUTION OF MOTORS FOR AIRCRAFT.

Application filed March 13, 1924, Serial No. 698,973, and in France April 5, 1923. Renewed October 13,

i It is commonly known that the efiiciency of an aerial motor varies with the altitude of the flight so that when the barometer indicates 38 cm. the efiiciency is reduced for about one half. The advantage, which would be obtained from the great altitudes where the resistanceto flight is less is consequently reduced by the loss of eliiciency of secure working, absorbing of capacity whereby for the same value the capacity of the motor is reduced and especially serious disturbances in the carburation.

This invention has for itsobject .to ensure that the motor supplies a constant efficiency, independently of the flight altitude, without auxiliary apparatus, turbines, or compressors and comprises improved means for rendering adjustable the angle of opening of the admission so that this admission be inversely proportional to the atmospheric pressure at the height of the flight.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming apart of this specification, with the understanding that while on the drawings one embodiment of the invention is disclosed, the invention is not confined to any strict conformity with the showing of thedrawin'gs, but may be embodied in any manner which does not make a material departure from the salient features of the invention.

In the drawing Fig. 1 shows the device which controls the valve rod.

Fig. 2 is a diagram relating to the running on the ground.

Fig. 3 is a diagram relating to the running of the motor at 4000 meters.

Fig; 4 is a diagram relating to the zero admission.

Figs. 5 and 6 are working diagrams relating respectively to the running on the ground and to the running of the motor at an altitude of 4000 meters.

Referring to Fig. 1, ais the admission cam of one of the cylinders, the piston being at the upper dead point, beginning of the suc-, tion. 6 is a lever carrying the roller 0 and acting with its end on the valverod (Z, said lever being adapted to oscillate around the axle 'e. The pivot axle e is journaled in two square bearing-blocks f sliding in two guides g, g. A-lever h fulcrumed at apermits of d1.sp1acingthe axle 6. This displacing can be controlled by an arm j of lever 2' either from the pilot in accordance with the altitude or by a pneumatic apparatus 70 similar to the lens of the aneroid barometer.

The acting surface a." of the cam a must be parallel with the axis m n along whichthe roller 0 is displaced so that" the opening of the valve takes place always at the dead point position whichever may bethe position of the roller.

The device operates according to the following ex lanations: For the running on.

the groun the position given to the roller 0 is that shown in Fig. 2, the angle of opening on and the admission being reduced by one ialf. The volume of the compression chamher being such that, notwithstanding the reduced admission the value at the end of the compression attains about 5, the effieiency of. the motor will be represented by any Value P.

For the running at 4000 meters the position given to the roller 0 is that indicated in Fig. 3. The angle of opening B is maximal, the admission is full and the compression, if the apparatus were on the ground, viz, with a barometrical pressure of 7 6 cm., would be much increased, to about 10. At 4000 meters however the barometric pressure has dropped to about 38 cm. and,

the volume of gas which is really admitted being about half of that which would be admitted on the ground, the compression at the end of the stroke will have only half of the volume on the ground 5. The engine works consequently with half-admission and a value of compression of 5. These conditions are identical to those of the running on the ground, the efficiency of the motor being also represented by P.

The forces on the ground and at altitude flight will, therefore, be the same, but the resistance of the air against the flight being however reduced by one half, the speed of the apparatus will be increased in aconsid erable proportion.

- of running on the ground with throttled gas (starting or slowed down running). It is evldent that these pos1t1ons can only be controlled by the pilot.

Fig. 5 is the diagram of the working on the ground and 6 the diagram of the working at 4.000 in. These diagrams show that, all other conditions being the same, the preliminary compressions having equal value on the ground and at e000 m., the explosions will have the same power, the areas of the diagrams and, consequently, the efliciencies of the motor will be constant with the exception of very slight differences. 7

It is understood that the indications of the drawing and the description relating to the same serve merely to explain the characteristic features of the invention by an embodiment given by way of example, other embodirnents possessing the same characteristic features being however possible.

I claim Improvements in the regulation of the internal combustion engines for flying machines with a View to obtaining from the engine a constant eiiicienc-y, without auxiliary apparatus, whatever might be the altitude of flight, comprising in combination with the usual admission valve, a lever controlling by one of its two arms said admission'valve, a roller in which said lever is pivotally mounted, a driving cam acting upon said roller, a bearing block pivotally connected with the end of the other arm of said lever, two guides between which said bearing block is adapted to slide according to the direction in which said lever moves, an elbow lever having its upper end hingedly connected with said bearing block, a pneumatic apparatus exposed to the action of the atmospheric pressure, and a connecting rod connecting said pneumatic apparatus with the lower end of said elbow lever.

In testimony whereof I affix my signature.

HENRY FARMAN. 

